Internal combustion engines, such as diesel or gasoline engines, generally include a cylinder block with a plurality of piston bores. In order to generate mechanical power, pistons reciprocate within the cylinder bores. Each of the cylinder bores typically include a replaceable cylinder liner sized to fit within the cylinder bore. The cylinder liner may generally be a cylindrically shaped sleeve that has an inner surface which serves as a sliding surface for the piston rings.
Cylinder liners provide numerous advantages to an internal combustion engine. For example, after significant wear of cylinder liners over time due to normal operation of the engine, the cylinder liners can be easily removed and replaced without replacing the entire cylinder block. Thus, most improvements in cylinder liners are directed to reducing wear of the liners, which may negatively impact engine performance.
One such improvement is disclosed in U.S. Patent Application Publication No. 2014/0216388 A1, entitled, “Engine Cylinder Mid-Stop.” The 2014/0216388 publication describes an engine cylinder mid-stop for supporting a cylinder liner. Formed in a side wall of the cylinder, the mid-stop includes a first contact surface and an undercut between the first contact surface and the side wall. The cylinder liner includes a second contact surface, which is supported by the first contact surface of the mid-stop. The undercut of the mid-stop reduces motion between the first and second contact surfaces, thereby reducing wear between the cylinder and liner. While effective, the 2014/0216388 publication only addresses the problem of cylinder liner wear.
However, further improvements in cylinder liners are desired to address problems other than wear of the cylinder liner. More specifically, the temperature within the O-ring groove of the cylinder liner may exceed material capabilities of the O-ring, thereby resulting in failure of the sealing joint and causing an external coolant leak. Accordingly, improvements in cylinder liners are needed to reduce O-ring groove temperatures.